Ion implantation is a process of depositing chemical species into a substrate by direct bombardment of the substrate with energized ions. In semiconductor manufacturing, ion implanters are used primarily for doping processes that alter the type and level of conductivity of target materials. A precise doping profile in an integrated circuit (IC) substrate and its thin-film structure is often crucial for proper IC performance. To achieve a desired doping profile, one or more ion species may be implanted in different doses and at different energies.
As critical dimensions of microelectronic devices continue to shrink, there have been ever increasing efforts to improve device performance and process yield. It has been discovered that high-temperature ion implantation (i.e., with a target wafer in a temperature range well above room temperature, such as 150-600° C.) may offer significant advantages over room-temperature ion implantation.
Although high-temperature ion implantation has been attempted, existing approaches suffer from a number of deficiencies. For example, high-temperature ion implantation techniques have been developed for batch-wafer ion implanters specialized for oxygen implantation while the current trend in the semiconductor industry favors single-wafer ion implanters capable of implanting multiple ion species.
In research environments, some high-temperature ion implantation has been performed in single-wafer ion implanters, often on small substrates mechanically held on sample manipulators. However, such research implementations do not have a high, production-worthy throughput for large substrates and often suffer from a high level of metal and particulate contamination.
In addition, plasma doping (PLAD) techniques are seeing an increased use in semiconductor manufacturing. Thus, there is also a need for high-temperature ion implantation with PLAD systems.
In view of the foregoing, it may be understood that there are significant problems and shortcomings associated with current temperature-controlled ion implantation technologies.